Sunscreens are supposed to prevent aging, sunburn, tanning, and skin cancer. Correct? The answer is “no,” however one might be tempted to say “yes” based on the marketing claims and information presented in the popular press. Sunscreens were never intended to prevent sunburn or tanning. Sunscreens only prolong the amount of sun exposure than can be received until burning or tanning occurs. Further, sunscreens have never been proven to prevent skin cancer.
It makes sense to assume that less sun exposure will result in less skin aging, but no one knows if wearing sunscreen decreases sun exposure sufficiently to reduce skin aging. New evidence indicates that visible light and infrared radiation also cause skin aging and these wavelengths are not blocked by sunscreens. This might indicate that sunscreens are not superb in preventing aging, but they are the best option currently available.
The safety of sunscreens has recently been called into question by several consumer groups purporting that sunscreens are proestrogenic and cause cancer. Much of the data to support these contentions comes from studies where rodents were fed massive amounts of sunscreen. Clearly, sunscreens are not intended for ingestion, but accidental ingestion does occur, especially in children. It is possible to isolate sunscreen actives from the urine of humans who use them, so we know that some systemic effects do occur.
Sunscreens are the most effective product currently available for photoprotection of the face, but the safety issues cannot be ignored. I would recommend the following:
1. Only wear sunscreen-containing products during the day when sun exposure may occur. Do not use sunscreen-containing moisturizers at night.Buy a separate product for nighttime application, cutting the sunscreen exposure in half.
2. Do not use sunscreens on children less than 6 months. Keep these infants out of the sun.
3. Only apply sunscreen on areas of the skin that will be exposed to sun and not under clothing.
4. Avoid ingesting the sunscreen when possible.
5. Wash the palms of the hands after applying sunscreen to avoid accidental ingestion when handling food.
There is nothing in life that is thoroughly safe, including the use of sunscreens. Everything must be assessed in terms of a risk/benefit ratio. Sunscreens have a very low risk/benefit ratio, but research is needed to better understand the protection of skin from the sun. The sun gives life and the sun takes away from the beauty of the skin.
About the Author
Zoe Diana Draelos, MD, is a practicing board-certified dermatologist and a Fellow of the American Academy of Dermatology with a research interest in cosmetics, toiletries and biologically active skin medications. She is in solo private practice in High Point, North Carolina, and a Consulting Professor of Dermatology at Duke University. In 1988, she founded Dermatology Consulting Services to provide education, develop formulations, and conduct clinical studies in association with industry. Prior to pursuing a medical career, Dr. Draelos completed an undergraduate degree in Mechanical Engineering and was elected a Rhodes Scholar. A member of Sigma Xi research honorary and Alpha Omega Alpha medical honorary, she is author of the textbooks Cosmetics in Dermatology and Hair Cosmetics, as well as the editor of Cosmeceuticals, now in its second edition and translated into five languages. She has contributed chapters to 32 textbooks, served as the principle investigator on 274 studies, written 270 published papers, serves on 8 journal editorial boards, functions as the editor-in-chief of the Journal of Cosmetic Dermatology, and was a past member of the Board of Directors of the American Academy of Dermatology and the American Society for Dermatologic Surgery. She is presently serving on the Council for Scientific Affairs for the Society of Cosmetic Chemists. Recently, she received a lifetime achievement award for her research from Health Beauty America and the DermArts award for her contributions to the practice of dermatology.